Turbochargers are typically used with an engine to improve the engine's volumetric efficiency. Turbochargers include a turbine wheel within a turbine housing. The turbine wheel is a rotating component that is used to extract energy from exhaust gases that pass through the turbine housing. Unfortunately, turbocharger turbines can catastrophically fail resulting in fragmentation of the turbine blades and hub. This type of failure is referred to as a burst and can have many root causes such as material contaminants, improper heat treat, inadequate attachment to the shaft, excessive temperature, and excessive rotational speed. Given the high rotation speeds of the turbine wheel, a burst failure can cause fragments of the turbine wheel to become dangerous projectiles.
Up until now, turbine housings were only designed to contain fragments of the turbine wheel that traveled in a radial direction from the turbine wheel. However, the fragments of the turbine wheel created by a burst failure do not always travel in a radial direction. In fact, the fragments could exit the turbine housing outlet and cause a great deal of damage to systems nearby, such as engine parts. There have been attempts to create an exhaust pipe, which attaches to the turbine housing to carry away exhaust gases, with cross bars for slowing down fragments of the turbine wheel that travel through the exhaust pipe. However, such exhaust pipe designs still permit fragments of the turbine wheel to break through the walls of the exhaust pipe, including those portions of the exhaust pipe between the cross bars and the turbine housing.
Accordingly, there exists a need for a turbine assembly that can contain flying fragments of turbine wheel in order to prevent them from escaping and harming other systems nearby.